Wound dressing



. April 1969 c. J. BURDA 3,439,676

WOUND DRES S ING Filed Dec. 1. 1966 INVENTOR. Char/es J Euro a HTTORNEYUnited States Patent 3,439,676 WOUND DRESSING Charles J. Burda, Midland,Mich., assignor to Dow Corning Corporation, Midland, Mich., acorporation of Michigan Filed Dec. 1, 1966, Ser. No. 598,327

Int. Cl. A61f 7/02 US. Cl. 128-268 5 Claims ABSTRACT OF THE DISCLOSUREAn improved wound dressing which is transparent and is composed of aself-adhering silicone elastomer having medicaments dispersed thereinwhich are controllably released to the siteof the wound.

This invention relates to an improved wound dressing and-the like. Moreparticularly, this invention relates to a wound dressing which possessesa multiplicity of desirable properties and hence, solves many problemsassociated with the application and performance of presently availabledressings.

Wound dressings which are now obtainable by the consumer are generallycomprised of some type of adhesive backed tape or the like which has apatch of cotton gauze or similar fabric attached thereto. The fabricportion of the dressing is applied to the surface of the wound and theadhesive readily adheres to the surrounding tissues maintaining thewound dressing in a fixed position.

To observe the progress of the wound, the dressing must be removed andreplaced frequently. Due to the strength of the bond existing betweenthe adhesive and the surrounding tissue, upon subsequent removal of thedressing extreme pain is often encountered. In addition, the affectedtissues may be unduly irritated resulting in the possibility ofsecondary infections and the like.

In the prior art dressings of the nature described above, the fabricthat is immediately in contact with the wound is normally attached tomaterial that is essentially nonporous. As a result, its non-porousnature will prevent air from easily permeating the material and findingits way to the wound. In many cases it is very desirable that the woundbe in contact with air for a substantial period of time and hence, thedressing must necessarily be removed during sleeping hours or at otherintervals. Such a procedure inevitably increases the risk that the Woundwill be repeatedly damaged in some manner which may extend the period ofrecovery at the expense of discomfort to the patient.

In the past, various medicaments have been incorporated in the fabric sothat the wound can be accorded the benefit of said medicaments. However,due to the types of fabrics employed, the medicament may be socompletely absorbed in the fabric that the wound receives onlynegligible amounts of medicament or the fabric absorbs so ineflicientlythat an excess of medicament can detrimentally contact the wound.

In accordance with the above, it is an object of the present inventionto provide a wound dressing or the like which avoids the aforesaiddisadvantages related herein.

Hence, it is an object of this invention to provide a wound dressingconsisting of a silicone elastomer impregnated with medication wherebythe medication is released to the site of the wound at a controlledrate.

It is also an object of the present invention to provide a wounddressing composed of a silicone elastomer that can be transparent,therefore permitting one to observe the progress of the wound absent theneed of frequent 3,439,676 Patented Apr. 22, 1969 removal of thedressing which was heretofore required for such a purpose.

It is still another object of this invention to provide an improvedwound dressing which is self-adhering, thus obviating the need foradhesive backed tape or a like material to maintain the dressing in itsfixed position. A further object is also apparent when the dressing hasselfadhering properties due to the fact that the amount of pressure thedressing exerts to the wound can be efficiently controlled. For example,if the wound is particularly receptive to slight pressure, this can besatisfactorily achieved. In contrast, if the Wound is receptice toextensivepressure, this can likewise be readily achieved.

Other objects and attendant advantages of the invention will becomeobvious to those skilled in the art from a consideration of thefollowing detailed description when read in conjunction with theaccompanying drawings wherein:

FIGURE 1 is a perspective view of a wound dressing constituting apreferred embodiment of the invention which has been applied to a wound.

FIGURE 2 is a perspective view of a wound dressing constituting anotherpreferred embodiment of the invention which has been applied to a wound.

Referring now to the drawings wherein like reference numerals designatelike or corresponding parts there is shown in FIGURE 1, a wound dressing11 of this invention applied about the arm and surrounding the wound 13.As shown, the wound dressing 11, is preferably transparent and hence,the wound 13 is clearly visible after the wound dressing 11 has beenappropriately applied. The decided advantage to be derived whenemploying a wound dressing 11 which is transparent and of the typedescribed herein is obvious since one is able to observe the progress ofthe wound without having to remove the dressing. As also shown, at thearea of attachment '12, the dressing is self-adhering and thus,eliminates the need for adhesive backed tape or other like adhesiveswhich are required to maintain prior art wound dressings in a fixedposition. The use of a self-adhering wound dressing also allows one tocontrol the pressure that the dressing imparts to the wound. Forexample, the dressing can be applied as loosely or as tightly as onewishes while still achieving the objects of the present invention.

It is of importance to note that the wound dressing of this inventionand as illustrated in FIGURE 1 has been impregnated with medicaments sothat the medicament is released to the wound after the dressing isapplied. Any desired quantity of medication may be impregnated in thedressing so that the wound will receive the required amount ofmedication while at the same time there is assurance that excessmedication shall not be deposited upon the wound. As a result, one caneffectively control the amount of medication the Wound receives bymerely controlling the quantity of medicament to be impregnated in thedressing.

The medicament is readily impregnated in the dressing by simplydispersing it in a suitable solvent and there after contacting thedressing with the dispersed solvent for a time suflicient to insure thatthe dressing has absorbed the required amount of medicament. Thesilicone elastomer, hereafter described, which is employed as thedressing is permeable to countless solvents, hence the desiredmedicament is readily absorbed by the dressing. The dressing is thenair-dried during which the solvent volatilizes while the medicamentremains absorbed. Any known solvent which will readily disperse themedicament and which will not perniciously or otherwise affect thedressing can be employed for such a purpose. Solvents which have beenfound to be satisfactory for such a purpose include chloroethylene,perchloroethylene, xylene, and ether, among numerous others.

FIGURE 2 is illustrative of another wound dressing Within thecontemplation of the present invention. There is shown a wound dressing21 of this invention applied about the arm and surrounding the wound 23.The dressing 21 is similar to that shown in FIGURE 1 with the exceptionthat it is composed of two identical layers 24 and 25. Both layers, 24and 25, are preferably transparent, hence the wound 23 is clearlyvisible after the Wound dressing 21 is appropriately applied. Inpractice the initial layer 24 is wrapped about the arm and surrounds thewound 23. After the initial layer 24 has been wrapped about the site ofthe wound 23, the desired medicament is applied to the surface of theinitial layer 24 in the general area of the wound. As a result, themedicament diffuses through the layer and contacts the wound 23.Subsequent to the above procedure, the second layer 25 is applied uponthe initial layer 24. At the area of attachment 22, the layer 25 isself-adhering and therefore, eliminates the need for adhesive backedtape or other like adhesives required to maintain prior art wounddressings in a fixed position.

The modification illustrated in FIGURE 2 is particularly advantageousfor a number of reasons. For example, as additional medication isrequired, the second layer 25, can be easily and rapidly removed and theadditional medicament placed on the surface of the initial layer 24. Inthis manner, the wound 23 remains covered; its pro-gress is stillobservable; and the wound is never disturbed. In fact, one need not evenremove the second layer 25 since the additional medication can befeasibly injected between the two layers 24 and 25 by use of ahypodermic needle or other like source.

The preferred embodiment described in FIGURE 2 is particularly suitablein situations where speed is an important factor. Thus, in battlefieldsituations where dressings must be removed and replaced rapidly oradditional medication must be applied quickly, the improved wounddressing of FIGURE 2 would be especially applicable.

Any known silicone elastomer that readily adheres to itself can besuitably employed in the present invention. It has been observed thatwhen strips of such elastomers in the form of tapes or the like aresuperimposed one upon the other so that the weight of the tapesconstitutes the only form of pressure, the superimposed elastomersurfaces effectively adhere to each other with an excellent bondexisting therebetween. Although the self-adhering elastomers of thisinvention will easily and readily adhere to themselves, they retaintheir releasability with respect to the wound. Therefore, the dressingdoes not stick to the wound and hence, effects a more rapid cure of theafilicted area. Illustrative of the self-adhering silicone elastomer andmethods for their preparation that are useful herein are thoseelastomers disclosed in US. Patents 3,050,490; 3,050,491; 3,070,567; and3,146,799, among numerous others.

In addition to the self-adhering properties which are characteristic ofthe above elastomers, they are also air permeable thus, theself-adhering elastomer inherently permits air to constantly passthrough the dressing and contact the wound which may increase the rateat which the wound heals.

Prior to use, the novel wound dressings of this invention are preferablyprepared in the form of a roll. Hence, after curing and impregnating theelastomer with the medicament, the dressing can be fed to winding rollsand wrapped about a core in overlapping fashion to provide a roll ofdressing of any desired size. Due to the characteristic self-adheringproperties, the dressing is normally wound upon itself with aninterlayer such as paper or plastic film between the overlappingsurfaces. While the dressing exhibits a tendency to adhere to suchsurfaces, the tendency is not sufficient to prevent removal of thedressing from the interlayer when occasion for its use arises. That is,due to the limited degree of adhesion which the dressing exhibitstowards the interlayer material, the concentric layers of dressing canbe easily unwound and the dressing can thereafter be readily strippedaway or otherwise removed from the interlayer material.

Materials which can be typically employed as an interlayer for the rollsof dressing are paper, nylon, and cellophane, as well as plasticmaterials such as the polymers and copolymers of vinyl chloride andpolyvinylidene chloride, Mylar (polyethylene terephthalate resin) andpolyolefins, such as polyethylene and polypropylene. If paper isemployed as the interlayer it is generally treated or coated with wax,such as parafiin wax, or other like material to limit the degree ofadhesion that the dressing exhibits towards the paper.

The interlayer materials described above can also be used to separateunrolled strips or flat sheets of the dressings of this invention. Thiscombination of a layer of dressing having at least one surface incontact with a layer of one of the materials toward which the dressingexhibits a limited degree of adhesion provides an efficient means forstoring or transporting the dressing. The dressing can be easilystripped away or otherwise removed from such materials when so desired.

Alternatively, powders such as talcum powder, baking soda, and the likecan be dusted on one surface of the dressing and when rolled, thedressing will not tend to adhere to itself. However, for practicalpurposes and other general considerations, the former method ofpreparting the dressings prior to use is most desired.

The invention has been described with reference to preferredembodiments, but it is to -be understood that these are by way ofillustration only. Accordingly, it is contemplated that modificationsand variations can be made in the operating techniques without departingfrom the spirit of the invention or the scope of the appended claims.

That which is claimed is:

1. A method for dressing a wound which comprises:

wrapping a wound with a band of self-adhering silicone elastomerimpregnated with a medicament so that the impregnated elastomer is incontact with the wound and the impregnated silicone elastomer is inself-adhering contact with itself.

2. The method as recited in claim 1 wherein the impregnated siliconeelastomeris transparent.

3. The method as recited in claim 2 wherein the selfadhering siliconeelastomer is impregnated with a medicament by dissolving said medicamentin a solvent and thereafter contacting the self-adhering siliconeelastomer with the dissolved medicament whereby the medicament isabsorbed by the self-adhering silicone elastomer after which the solventis evaporated.

4. The method as recited in claim 1 wherein the surface of said band istreated with a medicament and including the further step of thereafterwrapping a second band of a self-adhering silicone elastomer over thefirst band of self-adhering? silicone elastomer so that the said secondhand of self-adhering silicone elastomer is in selfadhering contact withitself.

5. The method as recited in claim 4 wherein the bands of self-adheringsilicone elastomer are transparent.

References Cited UNITED STATES PATENTS 3,050,490 8/1962 Nitzsche 2603753,297,032 1/1967 Antonik 128-268 3,342,183 9/1967 Edenbaum l28-268 ADELEM. EAGER, Primary Examiner.

US. Cl. X.R. l28-157

